Triazolocycloalkylthiadiazine derivatives

ABSTRACT

Novel triazolocycloalkylthiadiazines, their preparation, and use as antisecretory agents and central nervous system depressants.

SUMMARY OF THE INVENTION

This invention relates to new triazolocycloalkylthiadiazines, their method of preparation, compositions thereof, and their usefulness as pharmaceutical agents. More particularly, the novel compounds of this invention are derivatives of triazolocycloalkylthiadiazines which can be represented by the following structural formula ##SPC1##

Wherein R₁, R₂ and R₃ are each selected from the group consisting of hydrogen and lower alkyl having from 1 to 4 carbon atoms, inclusively; R₄ is selected from the group consisting of hydrogen, lower alkyl having from 1 to 4 carbon atoms, inclusively and oxo; R₅ is selected from the group consisting of hydrogen, alkyl having from 1 to 15 carbon atoms, inclusively, trifluoromethyl, cycloalkyl having from 3 to 6 carbon atoms, inclusively, phenyl, alkoxyalkyl having from 2 to 8 carbon atoms, inclusively and phenoxyalkyl having from 7 to 10 carbon atoms, inclusively; A is a sigma bond or the radical --(CH₂)_(n) -- in which n is a whole integer of from 1 to 7, inclusively; and the pharmaceutically acceptable acid addition salts thereof.

In general the triazolocycloalkylthiadiazine derivatives described herein are prepared by reacting in solution a 4-amino-4H-1,2,4-triazole-3-thiol with an α-haloalicyclic ketone. This reaction can be schematically represented as follows: ##SPC2##

In the above reaction sequence the symbols R₁, R₂, R₃, R₄, R₅ and A have the values previously assigned and X is halogen selected from the group consisting of chlorine, bromine and iodine.

In order to achieve an antisecretory or a central nervous system depressant effect, an effective amount of a compound of formula I is administered internally to an animal to be treated. Various pharmaceutical compositions including convenient dosage unit forms are also described.

BACKGROUND OF THE INVENTION

The treatment of conditions associated with gastric hyperacidity is almost as ancient as recorded history. Peptic and gastroduodenol ulcers have been variously treated both in the past and at present by means of bland diets, the exclusion of certain foods which are mechanically or chemically irritating and foods which do not stimulate gastric secretion.

Additionally, neutralizing drugs, which buffer or neutralize gastric contents; antispasmodics which reduce excessive gastroduodenal motor activity; sedatives which are used to induce general relaxation in ulcer patients; enzyme inhibitors which inhibit pepsin, the proteolytic enzyme secreted by gastric cells; nutritional supplements; mucosal protective agents and histamine antagonists have all been employed. Each of these drugs has its inadequacies as can be seen from the variety of drugs employed.

The most striking feature in the treatment of ulcers, has been a concern with gastric acidity. The rationale of gastric secretory depressant therapy lies in the hope that an agent can be found which will diminish or inhibit the process of hydrochloric acid formation in gastric cells without concomitant damage to these cells or harm to the host. The compounds of the present invention are antisecretory agents having a specific activity against gastric secretion in animals. Thus, they are useful for reducing or inhibiting gastric acid secretion and for the treatment of peptic ulceration. The term peptic ulceration is used in its broad sense, as is conventional in the art, to include both gastric ulceration and duodenal ulceration.

Additionally, these particular compounds are physiologically useful in view of their systemic depressant action upon the central nervous system of vertebrates. Thus, they can be administered either orally or parenterally to mammals for the relief of excessive anxiety and tension. Stress and anxiety are frequently associated as causative or contributing factors to the formation of ulcers. Thus, the compounds described herein are of particular benefit and usefulness not only in reducing gastric secretion, but also in their concomitant effect upon the central nervous system in the reduction of stress and anxiety.

The closest art known to applicant discloses a series of 5-alkyl-4amino-s-triazole-3-thiols stated to have analgetic and antiinflammatory activities, George et al., J. Med. Chem. 14, 335 (1971). Disclosed therein are four compounds containing a triazolothiadiazine nuclear moiety. These compounds lack the cycloalkyl portion of the nucleus and possess completely different pharmacological properties from those compounds claimed herein.

DETAILED DESCRIPTION OF THE INVENTION

As can be seen from general formula (I) and its description above, the compounds of the present invention include derivatives of triazolocycloalkylthiadiazine, which are substituted in both the triazole and cycloalkyl portions of the ring nucleus. The cycloalkyl ring can be unsubstituted, mono, di, tri or tetra-substituted as indicated by the symbols R₁, R₂, R₃ and R₄, which represents either hydrogen or a lower alkyl group having from 1 to 4 carbon atoms. The term "lower alkyl" refers to a univalent, aliphatic carbon side chain comprising such radicals as methyl, ethyl, propyl, isopropyl, butyl, isobutyl or tertiary-butyl.

Additionally, the symbol R₄ may also represent an oxo or ketone grouping at the 9-position of the triazolocycloalkylthiadiazine nucleus shown in formula (I). Derivatives of this type are capable of tautomerization as indicated below: ##SPC3##

Spectral evidence indicates that molecules of this type when isolated exist primarily in their enol form. For purposes of uniformity and nomenclature these tautomers are described as if they existed solely in their ketone form. Nevertheless, it is to be recognized that under conditions of therapeutic usefulness these derivatives may be present either as ketones or as their enol tautomers or as mixtures of both, depending upon various factors such as the nature of additional side chain substituents, pH of the medium, temperature and concentration. These tautomers and their mixtures are encompassed by the claims.

The triazole ring may remain unsubstituted or it can be mono-substituted at the 3-position with the substituents indicated by the symbol R₅. Thus, the symbol R₅ may represent an alkyl group, but in this instance the alkyl group can contain from 1 to 15 carbon atoms. In addition to the specific lower alkyl groups previously mentioned, the group R₅ also includes such radicals as amyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl and pentadecyl. Additionally, the various branched and positional isomers are included as long as the alkyl group is univalent and is not in excess of 15 carbon atoms.

The symbol R₅ may also represent a univalent cycloalkyl group having from 3 to 6 carbon atoms. Illustrative of such groups are the cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl radicals.

Certain univalent alkyl ethers are also represented by the symbol R₅. These ether moieties can be aliphatic in nature as when R₅ is alkoxyalkyl in which the carbon content of the alkoxyalkyl radical ranges from 2 to 8 carbon atoms. Illustrative members of this group include: methoxymethyl, methoxyisopropyl, methoxyheptyl, ethoxyethyl, ethoxyhexyl, propoxypropyl, propoxyisobutyl, isobutoxymethyl, amyloxymethyl, hexyloxyethyl and isoheptyloxymethyl. The ether moiety can also be aromatic in nature as represented by the expression phenoxyalkyl wherein the carbon content of the phenoxyalkyl radical ranges from 7 to 10 carbon atoms. Illustrative members of this group include: phenoxymethyl, phenoxyethyl, phenoxypropyl, phenoxyisopropyl, phenoxybutyl, phenoxyisobutyl and phenoxy-t-butyl. Specific univalent radicals encompassed by the symbol R₅ include the trifluoromethyl and phenyl radicals.

The symbol A represents either a sigma bond or the radical --(CH₂)_(n) -- wherein n is a whole integer of from 1 to 7 in order to encompass the various cycloalkyl moieties of the triazolocycloalkylthiadiazine nucleus. The expression "sigma bond" refers to the ordinary single bond linkage between two adjacent carbon atoms resulting from the overlap of their corresponding orbitals. Thus, where A represents a sigma bond the subgeneric class of triazolocyclopentylthiadiazines is delineated. Where A represents the radical --(CH₂)_(n) -- and n is the integer 1, the corresponding class of triazolocyclohexylthiadiazines is delineated and where n is the integer 7, the class of triazolocyclododecylthiadiazines is delineated. The various cycloalkyl moieties of the triazolocycloalkylthiadiazine nucleus encompassed herein include the cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl and the cyclododecyl moieties.

When the symbol R₄ is either hydrogen or lower alkyl, A is the radical --(CH₂)_(n) -- and n is the integer 1, a preferred subgenus is formed. Such compounds can be designated as triazolocyclohexylthiadiazines or 9-lower alkyl triazolocyclohexylthiadiazines. In addition to their antisecretory and central nervous system depressant activity, compounds of this group demonstrate anti-allergenic activity and antihypertensive activity.

Another preferred subgenus is formed when A is the radical --(CH₂)_(n) -- and n is an integer of from 2 to 3. Such compounds can be designated as triazolocycloheptylthiadiazines and triazolocyclooctylthiadiazines. Compounds of this group possess excellent anticonvulsant activity in addition to their antisecretory and central nervous system depressant activity.

Illustrative of the specific base compounds which are the subject of this invention are:

6,7,8,8a-tetrahydro-6-methyl-3-propyl-s-triazolo[3,4-b][1,3,4]cyclopentathiadiazine,

6,7,8,8a-tetrahydro-3-pentadecyl-8-propyl-s-triazolo[3,4-b][1,3,4]cyclopentathiadiazine,

7-t-butyl-3-cyclobutyl-6,7,8,8a-tetrahydro-s-triazolo[3,4-b][1,3,4]cyclopentathiadiazine,

6,7,8,8a-tetrahydro-3-methoxyheptyl-6,6-dimethyl-s-triazolo[3,4-b][1,3,4]cyclopentathiadiazin-8-one,

3-decyl-7,8,9,9a-tetrahydro-7,8-dimethyl-6H-s-triazolo[3,4-b][1,3,4]cyclohexathiadiazine,

3-trifluoromethyl-7,8,9,9a-tetrahydro-7l-isopropyl-8-methyl-6H-s-triazolo[3,4-b][1,3,4]cyclohexathiadiazine,

7,8,9,9a-tetrahydro-3-methoxyethyl-6H-s-triazolo[3,4-b][1,3,4]cyclohexathiadiazin-9-one,

9-butyl-7,8,9,9a-tetrahydro-7-methyl-3-phenoxypropyl-6H-s-triazolo[3,4-b][1,3,4]cyclohexathiadiazine,

6,7,8,9,10,10a-hexahydro-8-isopropyl-3-octyl-s-triazolo[3,4-b][1,3,4]cycloheptathiadiazine,

3-cyclopropyl-6,7,8,9,10,10a-hexahydro-8,8,9-trimethyl-s-triazolo[3,4-b][1,3,4]cycloheptathiadiazine,

6,7,8,9,10,10a-hexahydro-3-isoamyloxyethyl-8-methyl-s-triazolo[3,4-b][1,3,4]cycloheptathiadiazin-10-one,

9-t-butyl-6,7,8,9,10,10a-hexahydro-3-phenyl-s-triazolo[3,4-b][1,3,4]cycloheptathiadiazine,

11-ethyl-7,8,9,10,11,11a-hexahydro-3-isobutyl-9,9-dimethyl-6H-s-triazolo[3,4-b][1,3,4]cyclooctathiadiazine,

3,9-dimethyl-7,8,9,10,11,11a-hexahydro-6H-s-triazolo[3,4-b][1,3,4]cyclooctathiadiazine,

3-trifluoromethyl-7,8,9,10,11,11a-hexahydro-10-isobutyl-6H-s-triazolo[3,4-b][1,3,4]cyclooctathiadiazine,

7,8,9,10,11,11a-hexahydro-11-methyl-3-phenoxyisobutyl-6H-s-triazolo[3,4-b][1,3,4]cyclooctathiadiazine,

3-t-butyl-7,8,9,10,11,12,13,13a-octahydro-11,11,12,13-tetramethyl-6H-s-triazolo[3,4b][1,3,4]cyclodecathiadiazine,

3-cyclopentyl-7,8,9,10,11,12,13,13a-octahydro-12-methyl-6H-s-triazolo[3,4-b][1,3,4]cyclodecathiadiazin-13-one,

12-ethyl-7,8,9,10,11,12,13,13a-octahydro-11,11-dimethyl-3-nonyl-6H-s-traizolo[3,4-b][1,3,4]cyclodecathiadiazine,

3-hexyloxymethyl-7,8,9,10,11,12,13,13a-octahydro-12-isopropyl-6H-s-triazolo[3,4-b][1,3,4]cyclodecathiadiazine,

7,8,9-triethyl-7,8,9,10,11,12,13,14,15,15a-decahydro-3-isododecyl-6H-s-triazolo[3,4-b][1,3,4]cyclododecathiadiazine,

3-cyclohexyl-7,8,9,10,11,12,13,14,15,15a-decahydro-6H-s-triazolo[3,4-b][1,3,4]cyclododecathiadiazin-15-one,

7,7,8,9-tetraethyl-7,8,9,10,11,12,13,14,15,15a-decahydro-3-phenyl-6H-s-triazolo[3,4-b][1,3,4]cyclododecathiadiazine,

8,9-diethyl-7,8,9,10,11,12,13,14,15,15a-decahydro-3-phenoxymethyl-6H-s-triazolo[3,4-b][1,3,4]cyclodedecathiadiazine.

The expression "pharmaceutically acceptable acid addition salts" refers to any non-toxic inorganic or organic acid addition salts of the base compounds represented by formula (I) above. Illustrative inorganic acids which form suitable salts include hydrochloric, hydrobromic, sulfuric and phosphoric acid and acid metal salts such as sodium monohydrogen orthophosphate and potassium hydrogen sulfate. Illustrative organic acids which form suitable salts include the mono, di and tricarboxylic acids. Such acids include, for example, acetic, glycolic, lactic, pyruvic, malonic, succinic, glutaric, fumaric, malic, tartaric, citric, ascorbic, maleic, benzoic, p-hydroxybenzoic, phenylacetic, cinnamic, salicylic, 2-phenoxybenzoic and sulfonic acids such as methane sulfonic acid and 2-hydroxyethane sulfonic acid. Due to the fact that the triazolocycloalkylthiadiazines are relatively weak organic bases, the salts formed by the addition of strong inorganic mineral acids are more readily isolated and represent the preferred salts of this invention. In addition to salt formation, the free base compounds of this invention may exist in either a hydrated or a substantially anhydrous form. Generally speaking, the acid addition salts of these compounds are crystalline materials which are soluble in water and various hydrophilic organic solvents and in comparison to their free base forms, generally demonstrate a higher melting point and an increased chemical stability.

The starting materials used in the preparation of the compounds described herein are prepared via standard or known specific procedures. THus, the 4-amino-4H-1,2,4-triazole-3-thiols of formula (II) above can be prepared by the reaction of thiocarbohydrazide with an appropriate carboxylic acid or substituted carboxylic acid in accordance with the following reaction scheme: ##SPC4##

Where R₅ is phenyl, the procedure of Example 2 is employed.

In general, these reactants are heated together at temperatures ranging from 100° C. to about 160° C. in the presence or absence of a solvent for a period of about 1 to 12 hours. The resulting triazole can then be recovered using standard methods known to those skilled in the art.

The 2-halocycloalkanones of formula (III) above are either commercially available or can be readily prepared via the halogenation of their corresponding cycloalkanones. Suitable halogenating agents include bromine, chlorine, cupric bromide and sulfuryl chloride. The 1,3-diketones which are used in the preparation of the triazolocycloalkylthiadiazin-9-ones of formula (I) can be obtained by the halogenation of dimethyldihydroresorcinol using such halogenating agents as chlorine or bromine in a solvent such as chloroform or acetic acid. Illustrative of the diketones so produced are 2-bromocyclohexan-1,3-dione and 2-chloro-5,5-dimethylcyclohexan-1,3-dione. The 2-iodocycloalkanones and the 2-iodocycloalkane-1,3-diones can be prepared by treating the corresponding 2-chloro or 2-bromocycloalkanones or 1,3-diones with sodium or potassium iodide in acetone.

The compounds of the present invention are readily obtained by condensing the triazoles (II) with the ketones (III) described above in solution at an elevated temperature. Where either or both of the reactants are liquid in nature, condensation can be achieved by simple admixture and heating. Alternatively, the reaction can take place in a suitable inert solvent. Suitable non-reactive solvents include the lower alkanols, chloroform, dioxane, diethyl ether, tetrahydrofruan, pentane, hexane, heptane, benzene and toluene. The solvents of choice include the lower alkanols having from 1 to 6 carbon atoms, such as methanol, ethanol, isopropanol, amyl alcohol and n-hexanol, with ethanol representing the preferred solvent.

The temperature at which condensation takes place varies from about room temperature to about 150° C. Preferably, the condensation is conducted at temperatures which range from about 60° C. to about 100° C. in order to obtain maximum yields. As a matter of convenience, the reflux temperature of the reaction mixture is generally employed.

The reaction time is partly a function of the temperature employed, and partly a function of the degree of steric hindrance encountered. Additionally, the nature of the various substituents may necessitate adjusting the reaction period. A reaction time of about 1 hour to about 12 hours is generally sufficient for condensation to occur. Preferably, the reaction is conducted for about 1 to 2 hours in order to minimize any thermal degradation that may occur.

The desired products of this invention are generally prepared by concentrating the reaction mixture in vacuo to form an oily or solid residue. This residue can then be dissolved in an organic solvent such as chloroform or methylene chloride, and extracted with an aqueous alkaline solution, such as a 5 or 10% sodium hydroxide solution, in order to remove impurities and unreacted starting materials. The organic extract can be washed, dried and concentrated to obtain the desired product as a crude material. These crude products can be readily purified in a standard manner by recrystallization from ordinary solvent mixtures including methanol, ethanol, ethyl acetate, methylene chloride, hexane and pentane. The pharmaceutically acceptable acid addition salts can be prepared by recrystallization of the base compound from an acidified solvent, as for example, an ethanolic solution of hydrogen chloride. Alternatively, they can be prepared directly as illustrated in Example 7.

The compounds of the present invention and their nontoxic, pharmacologically acceptable acid addition salts, have useful pharmacodynamic properties. More particularly, the compounds of this invention exhibit effective stomach ulcer-inhibiting and stomach juice secretion-inhibiting activities in mammals, e.g., mice, rats, guinea pigs, gerbils, ferrets, dogs, cats, cows, horses and humans. The inhibiting action of the compounds claimed herein upon the rate of secretion of stomach juice and the amount of secreted total hydrochloric acid is ascertained in laboratory rats by means of a modification of the standard test method of Shay et al., Gastroenterology 5, 43-61 (1945).

The CNS depressant properties for these compounds are characterized as sedative depressants by their effect on pernicious preening in mice according to the procedure of Kandel et al., Fed. Proc., 19, 21 (1960). The compounds are further characterized as anticonvulsant-antianxiety agents as demonstrated by a modified method of Metrazol antagenism in mice, Goodman et al., J. Pharm. Exper. Therap., 108, 168 (1953).

For pharmaceutical purposes, the compounds of this invention can be administered to warm-blooded animals perorally or parenterally as active ingredients in customary dosage unit compositions. These compositions consist essentially of a dosage unit form containing the active ingredient and an inert pharmaceutical carrier. Dosage unit forms contemplated by the present invention include tablets, coated pills, capsules, dragees, lozenges, wafers, powders, elixirs, clear liquid solutions, suspensions, emulsions, syrups, and parenteral compositions such as intramuscular, intravenous or intradermal preparations. The quantity of active ingredient administered in such dosage forms can vary over a wide range depending upon the mode of administration, the size and weight of the particular mammal to be treated and whether the nature of the treatment is to be prophylactic or therapeutic in nature. In general, dosage unit forms contain from about 5 mg. to about 2.0 g. of the active ingredient, administered from 1 to 4 times daily. In general, a therapeutically effective amount of the active ingredient comprises from about 1 to about 200 mg/kg of body weight per day.

The excipients used in the preparation of the pharmaceutical compositions may be either organic or inorganic, solid or liquid in nature. Suitable solid excipients include gelatin, lactose, starches, magnesium stearate and petrolatum. Suitable liquid excipients include water and alcohols such as ethanol, benzyl alcohol and polyethylene glycols either with or without the addition of a suitable surfactant. In general, the preferred liquid excipients, particularly useful for injectable preparations, include water, saline solution, dextrose and glycol solutions, such as aqueous propylene glycol or an aqueous solution of polyethylene glycol. Liquid preparations to be used as sterile injectable solutions will ordinarily contain from about 0.5% to about 25% by weight, and preferably from about 1% to about 10% by weight, of the active ingredient in solution.

A preferred method of administration for the compounds of the present invention is peroral, either in a solid dosage form such as a tablet or capsule, or in a liquid form such as an oral elixir, suspension, emulsion or syrup. Tablets containing the active ingredient are prepared by mixing an inert diluent such as lactose in the presence of a disintegrating agent, e.g., maize starch and lubricating agents such as magnesium stearate. Such tablets can, if desired, be provided with enteric coatings using methods known to those skilled in the art, as for example, the use of cellulose acetate phthalate. Similarly, either hard or soft shelled gelatin capsules, can contain a compound of formula (I), with or without additional excipients and can be prepared by conventional means. Furthermore, if desired, such capsules can be provided with enteric coatings known to the art. Tablets and capsules can conveniently contain about 25-500 mg. of the active ingredient. Other less preferred compositions for oral administration include aqueous solutions, suspensions, emulsions, or syrups. Ordinarily, the active ingredient comprises from about 0.5% to about 10% by weight in such compositions. The pharmaceutical carrier is generally aqueous in nature, as for example, aromatic water, a sugar-based syrup or a pharmaceutical mucilage. For insoluble compounds, suspending agents can also be added as well as agents to control viscosity, as for example, magnesium aluminum silicate or carboxymethylcellulose. Buffers, preservatives, emulsifying agents and other excipients known to the art can also be added.

For parenteral administration such as intramuscular, intravenous or subcutaneous administration, the proportion of actie ingredient ranges from about 0.05% to about 20% by weight and preferrably from about 0.1% to about 10% by weight of the liquid composition. In order to minimize or eliminate irritation at the site of injection, such compositions may contain a non-ionic surfactant having a hydrophile-lipophile balance (HLB) of about 12 to about 17. The quantity of surfactant in such formulations ranges from about 5% to about 15% by weight. The surfactant can be a single surfactant having the above-identified HLB or a mixture of two or more components having the desired HLB. Illustrative of surfactants useful in parenteral formulations are the class of polyoxyethylene sorbitan fatty acid esters, as for example, sorbitan monooleate, and the high molecular weight adducts of ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol. The concentration of active ingredient contained in these various parenteral dosage unit forms varies over a broad range and comprises from about 0.05% to about 20% by weight of the total formulation, the remaining component or components consisting of those liquid pharmaceutical excipients previously mentioned.

Milk and milk solids are a valuable adjunctive therapy in the treatment of peptic ulcers, and the compositions of this invention include liquid and solid compositions based on milk and milk solids. The compounds of the present invention or the compositions thereof can, if desired, be associated with other compatable pharmacologically active ingredients. Thus, for example, antacids, and acid adsorbents such as aluminum hydroxide and magnesium trisilicate may also be included in compositions for oral administration in order to provide an immediate antacid effect. Other pharmacologically active ingredients that may be associated with the compounds of this invention include compounds affecting the central nervous system, as for example, long and short acting sedatives, such as barbiturates, antihistamimic agents, antiemetic agents such as cyclizine and diphenhydramine and anticholinergic agents such as atropine.

The invention described herein is more particularly illustrated by means of the following specific examples.

EXAMPLE 1 4-Amino-5-methyl-4H-1,2,4-triazole-3-thiol

Thiocarbohydrazine, 50 grams, is added to 600 ml. of acetic acid and heated to its reflux temperature for 30-45 minutes in an open flask. The solvent is evaporated until white crystals appear. The reaction mixture is heated to boiling to effect solution, and allowed to crystallize on cooling. The triazole so formed is collected by filtration, washed with water and dried at 60° C. in a vacuum oven to yield a compound having a m.p. of 209°-11° C. (dec.).

Following essentially the same procedure, but substituting formic acid, hexanoic acid, trifluoroacetic acid, cyclohexylcarboxylic acid, ethoxymethylacetic acid and phenoxypropylacetic acid for the acetic acid above results in the preparation of the following triazoles:

4-amino-4H-1,2,4-triazole-3-thiol,

4-amino-5-hexyl-4H-1,2,4-triazole-3-thiol,

4-amino-5-trifluoro-4H-1,2,4-triazole-3-thiol,

4-amino-5-cyclohexyl-4H-1,2,4-triazole-3-thiol,

4-amino-5-ethoxymethyl-4H-1,2,4-triazole-3-thiol, and

4-amino-5-phenoxypropyl-4H-1,2,4-triazole-3-thiol, respectively.

EXAMPLE 2 4-Amino-5-phenyl-4H-1,2,4-triazole-3-thiol

Benzoylhydrazide, 30.0 grams, is suspended in 90 ml. of ethanol to which is added 22.3 grams of carbon disulfide and a solution of 15 grams of potassium hydroxide in 20 ml. of water with stirring and cooling. After 30 minutes of stirring the reaction mixture solidifies and 19 ml. of water is added. Methyl iodide, 33.0 grams, is added via dropwise addition with continued stirring. After approximately 10 minutes the methyl ester crystallizes and is precipitated by the addition of 200 ml. of water. The crude methyl 2-benzoyldithiocarbazinate is removed by filtration and recrystallized from ethanol to yield 17 grams of a compound having a m.p. of 167°-8° C.

An 85% solution of hydrazine hydrate, 20 ml., methyl 2-benzoyldithiocarbazinate, 20 grams, and 80 ml. of ethanol are refluxed with stirring for a period of 4 hours. Upon cooling 200 ml. of water are added followed by 50 ml. of concentrated hydrochloric acid. The desired 4-amino-5-phenyl-4H-1,2,4-triazole-3-thiol is removed by filtration and recrystallized from a 50% aqueous ethanol solution to yield a compound having a m.p. of 200°-1° C.

EXAMPLE 3 2-Bromo-3-methylcyclohexanone

3-Methylcyclohexanone, 22.4 grams, contained in 250 ml. of chloroform and 50 ml. of ethyl acetate, is heated to boiling. A mixture of 98.3 grams of cupric bromide and 50 ml. of ethyl acetate is added and heated to maintain elimination of hydrogen bromide. When all of the hydrogen bromide is evolved, the mixture is heated to its reflux temperature for 15 minutes, filtered and the filtrate evaporated to a small volume. The residue is placed upon an alumina column and eluted with methylene chloride. Evaporation of the eluate yields 35.5 grams of crude 2-bromo-3-methylcyclohexanone suitable for condensation with the triazoles of Examples 1 or 2.

Following essentially the same procedure, but substituting

3,4-dipropylcyclopentanone,

5,5-dimethylcyclopentanone,

4,5,5-trimethylcyclohexanone,

5-ethyl-3,4-dimethylcycloheptanone,

4,5-diethylcyclooctanone.

cyclooctanone,

3-butylcyclodecanone,

dodecanone, and

3,4,5,5-tetramethylcyclododecanone

for the 3-methylcyclohexanone above results in the formation of

2-bromo-3,4-dipropylcyclopentanone

2-bromo-5,5-dimethylcyclopentanone,

2-bromo-4,5,5-trimethylcyclohexanone,

2-bromo-5-ethyl-3,4-dimethylcycloheptanone,

2-bromo-4,5-diethylcyclooctanone,

2-bromocyclooctanone,

2-bromo-3-butylcyclodecanone,

2-bromododecanone, and

2-bromo-3,4,5,5-tetramethylcyclododecanone, respectively.

EXAMPLE 4 4-t-Butyl-2-chlorocyclohexanone

The compound 4-t-butylcyclohexanone, 154.3 grams, is dissolved in 1 liter of benzene to which a trace of ferric chloride is added. The mixture is heated and 148.5 grams of sulfuryl chloride is added dropwise in periodic increments. The reaction mixture is slowly heated to its reflux temperature and maintained at that temperature until no further evolution of hydrochloric acid is observed. The solvent is removed in vacuo and the residue dissolved in a small amount of heptane. The solution is passed through an alumina column and the eluate removed by evaporation under reduced pressure to yield 167.6 grams of crude 4-t-butyl-2-chlorocyclohexanone.

Following essentially the same procedure but substituting

3-butylcyclopentanone,

4-propylcyclohexanone,

3-ethyl-5,5-dimethylcyclohexanone,

4-isopropylcycloheptanone,

3,4,5,5-tetraethylcycloheptanone,

3,5-diethylcyclooctanone,

3-t-butyl-5,5-dimethylcyclooctanone,

5-isobutyl-3-ethylcyclononanone, and

3-ethyl-5,5-dimethylcycloundecanone

for the 4-t-butylcyclohexanone above results in the formation of

3-butyl-2-chlorocyclopentanone,

2-chloro-4-propylcyclohexanone,

2-chloror-3-ethyl-5,5-dimethylcyclohexanone,

2-chloro-4-isopropylcycloheptanone,

2-chloro-3,4,5,5-tetraethylcycloheptanone,

2-chloro-3,5-diethylcyclooctanone,

3-t-butyl-2-chloro-5,5-dimethylcyclooctanone,

2-chloro-5-isobutyl-3-ethylcyclononanone, and

2-chloro-3-ethyl-5,5-dimethylcycloundecanone, respectively.

Refluxing the 2-chlorocycloalkanones so obtained with a solution of sodium iodide in acetone results in the formation of the corresponding 2-iodocycloalkanones.

EXAMPLE 5 2-Bromo-1,3-cyclohexanedione

1,3-cyclohexanedione, 100.0 grams, which is stabilized by the addition of a small amount of a 20% sodium chloride solution, is dissolved in 1 liter of hydrocarbon stabilized chloroform and anhydrous magnesium sulfate is added to remove water. The resulting solution is filtered, transferred to a three-necked flask equipped with stirrer, a condenser capped with a calcium chloride drying tube and a dropping funnel. A solution of 32 ml. of bromine is dissolved in 150 ml. of chloroform and added dropwise with stirring and stirring continued for an additional hour. The reaction product is removed by filtration, washed with cold chloroform and recrystallized from an ethanol-water mixture to yield 70.1 grams of 2-bromo-1,3-cyclohexanedione having a m.p. of 153°-4° C.

Following essentially the same procedure but substituting

4-ethyl-1,3-cyclopentanedione,

5,5-dimethyl-1,3-cyclohexanedione,

4,5-diethyl-1,3-cyclohexanedione,

4,5-diethyl-1,3-cycloheptanedione,

4-propyl-5,5-diethyl-1,3-cycloheptanedione,

4-propyl-5,5-diethyl-1,3-cyclooctanedione,

4-t-butyl-1,3-cyclooctanedione,

4,5-diemthyl-1,3-cyclodecanedione, and

4,5,5-trimethyl-1,3-cyclododecanedione

for the 1,3-cyclohexanedione above results in the formation of

2-bromo-4-ethyl-1,3-cyclopentanedione,

2-bromo-5,5-dimethyl-1,3-cyclohexanedione,

2-bromo-4,5-diethyl-1,3-cyclohexanedione,

2-bromo-4,5-diethyl-1,3-cycloheptanedione,

2-bromo-4-propyl-5,5-diethyl-1,3-cycloheptanedione,

2-bromo-4-propyl-5,5-diethyl-1,3-cyclooctanedione,

2-bromo-4-t-butyl-1,3-cyclooctanedione,

2-bromo-4,5-dimethyl-1,3-cyclodecanedione, and

2-bromo-4,5,5-trimethyl-1,3-cyclododecanedione, respectively.

EXAMPLE 6 3-Ethyl-6,7,8,8a-tetrahydro-s-triazolo[3,4-b][1,3,4]cyclopentathiadiazine

The compounds 2-chlorocyclopentanone, 17.8 grams, 4-amino-5-ethyl-4H-1,2,4-triazole-3-thiol, 21.6 grams, and 250 ml. of absolute ethanol are refluxed for a period of approximately 3.5 hours. A few ml. of methanolic hydrogen chloride are added and the reaction mixture is evaporated to dryness. The residue is dissolved in dilute hydrochloric acid and extracted with ether. The aqueous solution is made alkaline with a dilute aqueous solution of sodium hydroxide and twice extracted with methylene chloride. The methylene chloride extracts are combined, dried over anhydrous magnesium sulfate, filtered and evaporated to dryness. The crude 3-ethyl-6,7,8,8a-tetrahydro-s-triazolo[3,4-b][1,3,4]cyclopentathiadiazine so obtained is recrystallized twice from pentane to yield 16.4 grams of a product, m.p. 83°-5° C.

Following essentially the same procedure but substituting the various 4-amino-4H-1,2,4-triazole-3-thiols of Examples 1 and 2 and the various 2-chlorocycloalkanones of Example 4 for the 4-amino-5-ethyl-4H-1,2,4-triazole-3-thiol and 2-chlorocyclopentanone above results in the preparation of the corresponding s-triazolo[3,4-b][1,3,4]cycloalkathiadiazines.

EXAMPLE 7 6,7,8,9,10,10a-Hexahydro-3-methyl-s-triazolo[3,4-b][1,3,4]cycloheptathiadiazine hydrochloride

The compounds 4-amino-5-methyl-4H-1,2,4-triazole-3-thiol, 26.0 grams, 2-chlorocycloheptanone, 31.0 grams, and absolute ethanol, 500 ml., are stirred at their reflux temperature for a period of approximately 4 hours under anhydrous conditions (the reflux condenser is equipped with a calcium chloride drying tube), whereupon the reaction mixture is concentrated in vacuo to a dark oil. The oil is dissolved in 100 ml. of methanol and ethyl acetate, 600 ml., added to induce the desired compound to crystallize. Recrystallization of the crude product from a solution of methanolethyl acetate results in the preparation of 22.6 grams of 6,7,8,9,10,10a-hexahydro-3-methyl-s-triazolo[3,4-b][1,3,4]cycloheptathiadiazine hydrochloride having a m.p. of 170°-1°C.

Following essentially the same procedure but substituting

4-amino-4H-1,2,4-triazole-3-thiol,

4-amino-5-ethyl-4H-1,2,4-triazole-3-thiol,

4-amino-5-propyl-4H-1,2,4-triazole-3-thiol,

4-amino-5-heptyl-4H-1,2,4-triazole-3-thiol,

4-amino-5-phenoxymethyl-4H-1,2,4-triazole-3-thiol, and

4-amino-5-trifluoromethyl-4H-1,2,4-triazole-3-thiol

for the 4-amino-5-methyl-4H-1,2,4-triazole-3-thiol above results in the formation of the following hydrochloride salts, respectively:

6,7,8,9,10,10a-hexahydro-s-triazolo[3,4-b][1,3,4]cycloheptathiadiazine (m.p. 173°-4° C.),

3-ethyl-6,7,8,9,10,10a-hexahydro-s-triazolo[3,4-b][1,3,4]cycloheptathiadiazine (m.p. 143°-4° C.),

6,7,8,9,10,10a-hexahydro-3-propyl-s-triazolo[3,4-b][1,3,4]cycloheptathiadiazine (m.p. 123°-4° C.),

3-heptyl-6,7,8,9,10,10a-hexahydro-s-triazolo[3,4-b][1,3,4]cycloheptathiadiazine (m.p. 96°-7° C.),

6,7,8,9,10,10a-hexahydro-3-phenoxymethyl-s-triazolo[3,4-b][1,3,4]cycloheptathiadiazine (m.p. 155°-7° C.), and

6,7,8,9,10,10a-hexahydro-3-trifluoromethyl-s-triazolo[3,4-b][1,3,4]cycloheptathiadiazine, respectively.

EXAMPLE 8 7,8,9,9a-Tetrahydro-3-methoxymethyl-6H-s-triazolo[3,4-b][1,3,4]cyclohexylthiadiazine

The compounds 4-amino-5-methoxymethyl-4H-1,2,4-triazole-3-thiol, 32.0 grams, 2-chlorocyclohexanone, 28.0 grams, and absolute ethanol, 600 ml., are refluxed for about 4 hours. The reaction mixture is concentrated in vacuo to a brown oil. This oil is dissolved in 400 ml. of methylene chloride, extracted with two portions of 100 ml. each of a 10% aqueous NaOH solution, washed with a saturated NaCl solution, dried over anhydrous MgSO₄ and evaporated to an oily residue.

The addition of 100 ml. of a saturated NaCl solution results in the formation of crude oily crystals of the desired product, which are washed and triturated with ether to yield 31.0 grams of 7,8,9,9a-tetrahydro-3-methoxymethyl-6H-s-triazolo[3,4-b][1,3,4]cyclohexylthiadiazine. Recrystallization from a methylene chloride-hexane solution results in a m.p. of 62°-3° C.

Using essentially the same procedure, substituting

4-amino-4H-1,2,4-triazole-3-thiol,

4-amino-5-methyl-4H-1,2,4-triazole-3-thiol,

4-amino-5-trifluoromethyl-4H-1,2,4-triazole-3-thiol,

4-amino-5-ethyl-4H-1,2,4-triazole-3-thiol,

4-amino-5-propyl-4H-1,2,4-triazole-3-thiol,

4-amino-5-cyclopropyl-4H-1,2,4-triazole-3-thiol,

4-amino-5-heptyl-4H-1,2,4-triazole-3-thiol,

4-amino-5-tridecyl-4H-1,2,4-triazole-3-thiol,

4-amino-5-ethoxymethyl-4H-1,2,4-triazole-3-thiol,

4-amino-5-phenoxymethyl-4H-1,2,4-triazole-3-thiol,

4-amino-5-ethoxyethyl-4H-1,2,4-triazole-3-thiol,

4-amino-5-phenyl-4H-1,2,4-triazole-3-thiol, and

4-amino-5-butyl-4H-1,2,4-triazole-3-thiol

in lieu of the 4-amino-5-methoxymethyl-4H-1,2,4-triazole-3-thiol above results in the formation of the following compounds, respectively:

7,8,9,9a-tetrahydro-6H-s-triazolo[3,4-b][1,3,4]cyclohexylthiadiazine (m.p. 146°-7.5° C.),

7,8,9,9a-tetrahydro-3-methyl-6H-s-triazolo[3,4-b][1,3,4]cyclohexylthiadiazine (m.p. 103°-4° C.),

7,8,9,9a-tetrahydro-3-trifluoromethyl-6H-s-triazolo[3,4-b][1,3,4]cyclohexylthiadiazine (m.p. 100°-1° C.),

3-ethyl-7,8,9,9a-tetrahydro-6H-s-triazolo[3,4-b][1,3,4]cyclohexylthiadiazine (m.p. 69°-70° C.),

7,8,9,9a-tetrahydro-3-propyl-6H-s-triazolo[3,4-b][1,3,4]cyclohexylthiadiazine (m.p. 73°-4° C.),

3-cyclopropyl-7,8,9,9a-tetrahydro-6H-s-triazolo[3,4-b][1,3,4]cyclohexylthiadiazine (m.p. 118°-9° C.),

3-heptyl-7,8,9,9a-tetrahydro-6H-s-triazolo[3,4-b][1,3,4]cyclohexylthiadiazine (m.p. 66°-7° C.),

7,8,9,9a-tetrahydro-3-tridecyl-6H-s-triazolo[3,4-b][1,3,4]cyclohexylthiadiazine (m.p. 84°-5° C.),

7,8,9,9a-tetrahydro-3-ethoxymethyl-6H-s-triazolo[3,4-b][1,3,4]cyclohexylthiadiazine (m.p. 78.5°-9.5° C.),

7,8,9,9a-tetrahydro-3-phenoxymethyl-6H-s-triazolo[3,4-b][1,3,4]cyclohexylthiadiazine (m.p. 116°-7° C.),

3-ethoxyethyl-7,8,9,9a-tetrahydro-6H-s-triazolo[3,4-b][1,3,4]cyclohexylthiadiazine (m.p. 78°-9° C.),

7,8,9,9a-tetrahydro-3-phenyl-6H-s-triazolo[3,4-b][1,3,4]cyclohexylthiadiazine (m.p. 187°-8° C.), and

3-butyl-7,8,9,9a-tetrahydro-6H-s-triazolo[3,4-b][1,3,4]cyclohexylthiadiazine as the free base compounds, respectively.

Substituting 4-amino-5-ethyl-4H-1,2,4-triazole-3-thiol for the 4-amino-5-methoxymethyl-4H-1,2,4-triazole-3-thiol above and 2-chloro-4-ethylcyclohexanone and 4-t-butyl-2-chlorocyclohexanone for the 2-chlorocyclohexanone above results in the preparation of

3,8-diethyl-7,8,9,9a-tetrahydro-6H-s-triazolo[3,4-b][1,3,4]cyclohexylthiadiazine (m.p. 76°-9° C.), and

8-t-butyl-3-ethyl-7,8,9,9a-tetrahydro-6H-s-triazolo[3,4-b][1,3,4]cyclohexylthiadiazine (m.p. 130°-2° C.), respectively.

Substituting 4-amino-5-methyl-4H-1,2,4-triazole-3-thiol and 2-chloro-3-methylcyclohexanone for the 4-amino-5-methoxymethyl-4H-1,2,4-triazole-3-thiol and 2-chlorocyclohexanone above results in the preparation of 7,8,9,9a-tetrahydro-3,7-dimethyl-6H-s-triazolo[3,4-b][1,3,4]cyclohexylthiadiazine having a m.p. of 124°-7° C.

The corresponding 2-chlorocycloheptanones and 2-chlorocyclooctanones can be substituted for the various 2-chlorocyclohexanones of this Example to prepare the analogous substituted 6,7,8,9,10,10a-hexahydro-s-triazolo[3,4-b][1,3,4]cycloheptathiadiazines and 7,8,9,10,11,11a-hexahydro-6H-s-triazolo[3,4-b][1,3,4]cyclooctathiadiazines.

EXAMPLE 9 3,7,7-Trimethyl-7,8,9,9a-tetrahydro-6H-s-triazolo[3,4-b][1,3,4]cyclohexathiadiazine-9-one

The compounds 2-bromodimedone, 66.0 grams, 4-amino-5-methyl-4H-1,2,4-triazole-3-thiol, 39.0 grams, and 1450 ml. of absolute ethanol are stirred at the reflux temperature for approximately 4 hours. The solvent is removed in vacuo, the residue dissolved in 800 ml. of 5% NaOH, filtered, and the filtrate acidified with 5% HCl. The desired 3,7,7-trimethyl-7,8,9,9a-tetrahydro-6H-s-triazolo[3,4-b][1,3,4]cyclohexathiadiazin-9-one which precipitates, is filtered and recrystallized three times from ethanol to yield a product having a m.p. of 245°-6° C.

Substituting 4-amino-5-trifluoromethyl-4H-1,2,4-triazole-3-thiol and 4-amino-5-ethoxyethyl-4H-1,2,4-triazole-3-thiol for the 4-amino-5-methyl-4H-1,2,4-triazole-3-thiol above results in the preparation of the corresponding 7,7-dimethyl-7,8,9,9a-tetrahydro-3-trifluoromethyl-6H-s-triazole[3,4-b][1,3,4]cyclohexathiadiazin-9-one (m.p. 225°-6° C.) and 3-ethoxyethyl-7,7-dimethyl-7,8,9,9a-tetrahydro-6H-s-triazole[3,4-b][1,3,4]cyclohexathiadiazin-9-one (m.p. 206°-7° C.), respectively.

Substituting 4-amino-5-ethyl-4H-1,2,4-triazole-3-thiol and 4-amino-5-ethoxymethyl-4H-1,2,4-triazole-3-thiol for the 4-amino-5-methyl-4H-1,2,4-triazole-3-thiol above and 2-bromo-1,3-cyclohexanedione for the 2-bromodimedone above results in the preparation of 3-ethyl-7,8,9,9a-tetrahydro-6H-s-triazolo[3,4-b][1,3,4]cyclohexathiadiazin-9-one (m.p. 223°-4° C.) and 3-ethoxymethyl-7,8,9,9a-tetrahydro-6H-s-triazolo[3,4-b][1,3,4]cyclohexathiadiazin-9-one (m.p. 205°-7° C.), respectively.

EXAMPLE 10 7,8,9,10,11,11a-Hexahydro-3-methyl-6H-s-triazolo[3,4-b][1,3,4]cyclooctathiadiazine hydrochloride

The compounds, 4-amino-5-methyl-4H-1,2,4-triazole-3-thiol, 78 grams, 2-chlorocyclooctanone, 10.0 grams, and 300 ml. of absolute ethanol are stirred at the reflux temperature for a period of about 4 hours. The solvent is removed in vacuo and the residue crystallized from a methanol-ethyl acetate mixture to yield approximately 9.3 grams of 7,8,9,10,11,11a-hexahydro-3-methyl-6H-s-triazolo[3,4-b][1,3,4]cyclooctathiadiazine hydrochloride having a melting point of 187°-9° C.

Following essentially the same procedure and substituting

4-amino-5-ethyl-4H-1,2,4-triazole-3-thiol,

4-amino-5-propyl-4H-1,2,4-triazole-3-thiol,

4-amino-5-heptyl-4H-1,2,4-triazole-3-thiol, and

4-amino-5-ethoxymethyl-4H-1,2,4-triazole-3-thiol

for the 4-amino-5-methyl-4H-1,2,4-triazole-3-thiol above results in the preparation of

3-ethyl-7,8,9,10,11,11a-hexahydro-6H-s-triazolo[3,4-b][1,3,4]cyclooctathiadiazine (m.p. 94°-5° C.) as the free base,

7,8,9,10,11,11a-hexahydro-3-propyl-6H-s-triazolo[3,4-b][1,3,4]cyclooctathiadiazine as the hydrochloride salt (m.p. 144°-5° C,),

3-heptyl-7,8,9,10,11,11a-hexahydro-6H-s-triazolo[3,4-b][1,3,4]cyclooctathiadiazine as the hydrochloride salt (m.p. 119°-20° C.), and 3-ethoxymethyl-7,8,9,10,11,11a-hexahydro-6H-s-triazolo[ 3,4-b][1,3,4]cyclooctathiadiazine (m.p. 93°-4° C.) as the free base, respectively.

EXAMPLE 11 7,8,9,10,11,12,13,14,15,15 a-Decahydro-3-methyl-6H-s-triazolo[ 3,4-b][1,3,4]cyclododecathiadiazine

The compounds, 4-amino-5-methyl-4H-1,2,4-triazole-3-thiol, 21.0 grams, 2-bromocyclododecanone, 40.0 grams, and 400 ml. of absolute ethanol are stirred at the reflux temperature for about 4 hours. The solvent is removed in vacuo and the residue is dissolved in 250 ml. of methylene chloride. The organic solution is extracted twice with 100 ml. portions of an aqueous 10% NaOH solution, followed by 200 ml. of an aqueous saturated NaCl solution, dried over anhydrous MgSO₄, concentrated to approximately 100 ml. and hexane added to form a yellow powder. Recrystallization from a methylene chloride-hexane solution yields 7,8,9,10,11,12,13,14,15,15a-decahydro-3-methyl-6H-s-triazolo[3,4-b][1,3,4]cyclododecathiadiazine having a m.p. of 138°-9° C.

Following essentially the same procedure but substituting 4-amino-5-ethyl-4H-1,2,4-triazole-3-thiol for the 4-amino-5-methyl-4H-1,2,4-triazole-3-thiol above, results in the preparation of 7,8,9,10,11,12,13,14,15,15a-decahydro-3-ethyl-6H-s-triazolo[3,4-b][1,3,4]cyclododecathiadiazine as the hydrochloride salt having a m.p. of 155°-7° C.

EXAMPLE 12 Antisecretory Activity

Male Sprague-Dawley rats weighing 200-250 grams each are fasted 48 hours prior to testing. Water is given ad lib for the first 24 hour period after which the water is replaced with an aqueous 10% dextrose and 0.5% sodium chloride solution. Six rats per compound group are treated as follows.

Under light anesthesia, a ventral midline incision approximately 10 mm. in length is made below the sternum. The duodenal bulb is revealed and the pyloric sphincter is tightly ligated with surgical silk being careful to avoid rupturing the surrounding blood vessels.

The compound to be tested, 7,8,9,10,11,11a-hexahydro-3-methyl-6H-s-triazolo[3,4-b][1,3,4]cyclooctathiadiazine, is administered as the hydrochloride salt by injection into the duodenum at a point distal to the ligature at a dosage of 25 mg/kg of body weight in an aqueous suspension of 0.1 ml/100 grams of body weight, said suspension containing 0.5% of hydroxyethylcellulose as a suspending agent. Four milliliters of water are injected into the stomach near the pyloric sphincter to provide a uniform amount of stomach distension in order to trigger gastric flow. The incisions are closed and the rats are injected i.p. with 2 ml. of physiological saline to restore fluid loss which occurs during surgery.

Following a 4 hour recovery period, the rats are sacrificed and their stomach contents harvested. The stomach contents are centrifuged at 1500 r.p.m. for 10 minutes and the volume and pH recorded. Control groups containing a mean volume of less than 8.0 ml. indicate an invalid test. The gastric contents of both control and test groups of animals are titrated against a standard solution of 0.1N sodium hydroxide.

Utilizing this procedure in three separate experiments, the compound 7,8,9,10,11,11a-hexahydro-3-methyl-6H-s-triazolo[3,4-b][1,3,4]cyclooctathiadiazine exhibits a reduction of 78%, 73% and 72% of total gastric acidity when compared to the control animals.

EXAMPLE 13 Tablet Formulation

An illustrative preparation for tablets is as follows:

                               Per                                                 Ingredients                Tablet                                              ______________________________________                                         (a)    7,8,9,10,11,11a-hexahydro-3-methyl-                                            6H-s-triazolo[3,4-b][1,3,4]cyclo-                                              octathiadiazine hydrochloride                                                                          150 mg.                                         (b)    Wheat starch and granulated starch                                             paste (10% w/v)         15 mg.                                          (c)    Lactose                 33.5 mg.                                        (d)    Magnesium stearate      1.5 mg.                                         ______________________________________                                    

The granulation obtained upon mixing lactose, starch and granulated starch paste is dried, screened and mixed with the active ingredient and magnesium stearate. The mixture is compressed into tablets weighing 200 mg. each.

EXAMPLE 14 Capsule Preparation

An illustrative preparation for hard gelatin capsules is as follows:

                              Per                                                  Ingredients               Capsule                                              ______________________________________                                         (a)    6,7,8,9,10,10a-hexahydro-3-methyl-                                             s-triazolo[3,4-b][1,3,4]cyclo-                                                 heptathiadiazine hydrochloride                                                                        200 mg.                                          (b)    Talc                    35 mg.                                          ______________________________________                                    

The formulation is prepared by passing the dry powders of both (a) and (b) through a fine mesh screen and mixing them well. The mixed powders are then filled into No. 0 hard gelatin capsules at a net fill of 235 mg. per capsule.

Soft gelatin capsules can be prepared in a similar fashion. Alternatively, the talc may be omitted and the active ingredient filled directly as a granulation, slug or compressed tablet into the rotary die or plate mold in which the soft gelatin capsule is to be formed.

EXAMPLE 15 Preparation of Parenteral Formulation

An illustrative composition for a parenteral injection is the following emulsion:

    Each ml                                                                        Contains  Ingredients         Amount                                           ______________________________________                                         50 mg.    7,8,9,9a-tetrahydro-3-                                                         methoxymethyl-6H-s-triazolo                                                    [3,4-b][1,3,4]cyclohexathia-                                                   diazine             1.0     g.                                       100 mg.   Polyoxyethylene sorbitan                                                       monooleate          2.0     g.                                       0.00064 mg.                                                                              Sodium chloride     0.128   g.                                                 Water for injection, q.s.                                                                          20      ml.                                      ______________________________________                                    

The parenteral composition is prepared by dissolving 0.64 g. of sodium chloride in 100 ml. of water for injection, mixing the polyoxyethylene sorbitan monooleate with the 7,8,9,9a-tetrahydro-3-methoxymethyl-6H-s-triazolo[3,4-b][1,3,4]cyclohexathiadiazine, adding a sufficient solution of the sodium chloride in water to the active ingredient and polyoxyethylene sorbitan monooleate to bring the volume to 20 ml., shaking the mixture, and finally autoclaving the mixture for 20 minutes at 110° C., at 15 p.s.i.g. steam pressure. The composition can be dispensed either in a single ampule for subsequent use in multiple dosages or in groups of 10 and 20 ampules for a single dosage administration.

EXAMPLE 16 Preparation of an Oral Syrup

A 2 percent weight per volume of syrup containing 7,8,9,9a-tetrahydro-3,9-dimethyl-6H-s-triazolo[3,4-b][1,3,4]cyclohexathiadiazine is prepared by the usual pharmaceutical techniques in accordance with the following formula:

    Ingredients                Grams                                               ______________________________________                                         (a)     7,8,9,9a-tetrahydro-3,9-dimethyl-                                              6H-s-triazolo[3,4-b][1,3,4]cyclo-                                              hexathiadiazine        2.0                                             (b)     Sucrose                33.0                                            (c)     Chloroform             0.25                                            (d)     Sodium benzoate        0.4                                             (e)     Methyl p-hydroxybenzoate                                                                              0.02                                            (f)     Vanillin               0.04                                            (g)     Glycerol               1.5                                             (h)     Purified water to 100.0 ml.                                            ______________________________________                                     

What is claimed is:
 1. A triazolocycloalkylthiadiazine having the formula: ##SPC5##wherein R₁, r₂ and R₃ are each selected from the group consisting of hydrogen and lower alkyl having from 1 to 4 carbon atoms; R₄ is selected from the group consisting of hydrogen, lower alkyl having from 1 to 4 carbon atoms and oxo; R₅ is selected from the group consisting of hydrogen, alkyl having from 1 to 15 carbon atoms, trifluoromethyl, cycloalkyl having from 3 to 6 carbon atoms, phenyl, alkoxyalkyl having from 2 to 8 carbon atoms and phenoxyalkyl having from 7 to 10 carbon atoms; A is a sigma bond or the radical --(CH₂)_(n) -- in which n is a whole integer of from 1 to 7; and the pharmaceutically acceptable acid addition salts thereof.
 2. A compound according to claim 1 wherein R₄ is hydrogen or lower alkyl; A is the radical --(CH₂)_(n) -- and n is the integer
 1. 3. A compound according to claim 1 wherein A is the radical --(CH₂)_(n) -- and n is an integer of from 2 to
 3. 4. The compound 7,8,9,10,11,11a-hexahydro-3-methyl-6H-s-triazolo[3,4-b][1,3,4]cyclooctathiadiazine and its pharmaceutically acceptable acid addition salts.
 5. The compound 6,7,8,9,10,10a-hexahydro-3-methyl-s-triazolo[3,4-b][1,3,4]cycloheptathiadiazine and its pharmaceutically acceptable acid addition salts.
 6. The compound 7,8,9,9a-tetrahydro-3-methoxymethyl-6H-s-triazolo[3,4-b][1,3,4]cyclohexylthiadiazine.
 7. A method of preparing a triazolocycloalkylthiadiazine having the formula ##SPC6##wherein R₁, R₂ and R₃ are each selected from the group consisting of hydrogen and lower alkyl having from 1 to 4 carbon atoms; R₄ is selected from the group consisting of hydrogen, lower alkyl having from 1 to 4 carbon atoms and oxo; R₅ is selected from the group consisting of hydrogen, alkyl having from 1 to 15 carbon atoms, trifluoromethyl, cycloalkyl having from 3 to 6 carbon atoms, phenyl, alkoxyalkyl having from 2 to 8 carbon atoms and phenoxyalkyl having from 7 to 10 carbon atoms; A is a sigma bond or the radical --(CH₂)_(n) -- in which n is a whole integer of from 1 to 7; and a pharmaceutically acceptable acid addition salt thereof which comprises reacting a 4-amino-4H-1,2,4-triazole-3-thiol having the formula ##SPC7## in which R₅ is as defined above; reacting said triazole with a 2-halocycloalkanone having the formula ##SPC8## in which R₁, R₂, R₃, R₄ and A are as defined above and X is halogen selected from the group consisting of chlorine, bromine and iodine, at a temperature ranging from room temperature to 150° C. and for a period of time ranging from 1 to 12 hours.
 8. A method of reducing gastric acid secretion which comprises administering a therapeutically effective amount of a triazolocycloalkylthiadiazine of claim 1 to mammals in need thereof.
 9. A method according to claim 8 in which the triazolocycloalkylthiadiazine is administered in an amount of from 1 to 200 mg./kg. of body weight per day.
 10. A therapeutic composition in dosage unit form comprising from 5 milligrams of 2.0 grams of a compound of claim 1 and a pharmaceutical carrier. 